Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Study puts notch on the jagged edge of lung cancer metastasis

Jagged2 promotes lung cancer metastasis by stifling a microRNA

Researchers discovered a new, key component in the spread of lung cancer as well as a likely way to block it with drugs now in clinical trial. The study was published today (Monday, March 14) in the Journal of Clinical Investigation.

A team led by scientists at The University of Texas MD Anderson Cancer Center found a way to identify metastasis-prone lung cancer cells and then uncovered a mechanism that shifts primary tumor cells into a more deadly type of cell with the capacity to move elsewhere in the body.

"We think tumors have to learn how to metastasize because they can't do it initially," said paper senior author Jonathan Kurie, M.D., professor in MD Anderson's Department of Thoracic/Head and Neck Medical Oncology. "Cells change in response to cues from their external environment."

About 90 percent of all cancer deaths are caused by metastasis - the spread to, and invasion of, other organs. Lung cancer is the leading cause of cancer-related death in the United States, accounting for more than 157,000 deaths annually. The median five-year survival rate is 3.5%

Jagged2 silences protective microRNA

The researchers found that when a protein called Jagged2 binds externally to Notch, a membrane protein that sticks out through the surface of a cell, it suppresses a microRNA that thwarts metastasis inside the cell.

"Jagged2 suppresses miR-200 and drives metastasis as a consequence." Kurie said. "It's been known for some time that Notch is involved in cancer, but no one really knew how."

Two Notch inhibitors are in clinical trial at MD Anderson. "These drugs might suppress the ability of primary tumors to metastasize," Kurie said.

"One question is who is supposed to get these drugs," Kurie said. "Our data suggest that low levels of miR-200 may indicate a tumor's susceptibility to Notch inhibitors."

Jailing tumor cells

While the drugs don't kill a primary tumor, they do "keep the primary lung tumors in jail," holding them in place and blocking their transition to mobile cells, Kurie said.

This transition, from immobile epithelial cells, which line or cover an organ, to a migratory cell with the properties of a mesenchymal cell, is an early event in metastasis. Kurie and colleagues previously showed that miR-200 blocks this epithelial-to-mesenchymal transition. About 80 percent of all cancers begin in the epithelial cells of organs.

Telltale surface protein identifies metastatic cells

The first crucial research step was to identify and study non-small cell lung cancer cells prone to metastasizing.

Yanan Yang, Ph.D., study first author and a postdoctoral fellow in Kurie's lab, studied lung cancer cells in mice, searching for markers of metastasis. He homed in on a surface protein called CD133.

"In primary lung tumors, CD133 cells are under 1 percent of cells," Yang said. "In metastatic lesions, more than 80 percent of the cells have CD133."

Follow up studies determined that CD133-expressing cells were located on the perimeter of tumors, ideally situated for metastasis. More than half of mice injected with CD133-positive lung cancer cells had metastatic cancer, compared to less than 20 percent of those injected with CD133-negative cells.

Intensive study of CD133 metastatic cells revealed that they highly expressed Notch ligands (proteins that bind to specific receptors on other cells). Yang said they separately depleted two Notch ligands - Jagged1 and Jagged2 - from tumor cells. Removing Jagged1 had no effect, but cells with little Jagged2 did not metastasize.

"Because epithelial-to-mesenchymal transition (EMT) is a very early step in metastasis," Yang said, "we thought Jagged2 might regulate EMT." When they knocked down Jagged2 again, they found levels of the EMT-stifling miR-200 increased.

External signals drive change

Additional research found that Jagged2 reduced miR-200 by tipping a delicate balance between the microRNA and a protein called GATA3, which inhibit one another. Stimulating production of more GATA3 reduced levels of miR-200.

"Jagged2 increases the levels of GATA3, which in turn binds to the promoter of miR-200 and suppresses production of miR-200," Yang said.

"The study is among the first to show that mir-200 is regulated by specific signals emanating from the environment surrounding cancer cells. These signals are keys to understanding metastasis", Yang said.

One surprise, Kurie said, is that GATA proteins had been thought to suppress tumors. "In this case it's exactly the opposite."

The next step is to determine which of the four known Notch receptors suppress miR-200 and promote metastasis. The drugs currently under study are designed to inhibit an enzyme that cleaves and activates all Notch receptors. Drugs that target specific Notch receptors might be more effective inhibitors of metastasis, Kurie said.

Funding for the project was provided by grants from the National Cancer Institute, MD Anderson's Lung Cancer Specialized Program in Research Excellence grant from NCI, the David M. Sather Memorial Fund, The Armour Family Lung Cancer Research Fund, the Dan L. Duncan Cancer Center at Baylor College of Medicine, The ASCO Cancer Foundation, and the International Association for the Study of Lung Cancer.

Co-authors with Yang and Kurie were Young-Ho Ahn, Don L. Gibbons, Yi Zang, Wei Lin, Nishan Thilaganthan, Cristina A. Alvarez, and Daniel C. Moreira, of MD Anderson's Department of Thoracic/Head and Neck Medical Oncology; Moreira also is with the Medical School, Tecnológico de Monterrey, Monterrey, Mexico; Chad J. Creighton, Dan L. Duncan Cancer Center, Baylor College of Medicine; and Philip A. Gregory and Gregory J. Goodall of the Centre for Cancer Biology, Hanson Institute, Adelaide, South Australia, Australia, and Discipline of Medicine, University of Adelaide, Adelaide, South Australia, Australia.

About MD Anderson

The University of Texas MD Anderson Cancer Center in Houston ranks as one of the world's most respected centers focused on cancer patient care, research, education and prevention. MD Anderson is one of only 40 comprehensive cancer centers designated by the National Cancer Institute. For seven of the past nine years, including 2010, MD Anderson has ranked No. 1 in cancer care in "America's Best Hospitals," a survey published annually in U.S. News & World Report.

Scott Merville | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>